D, R, A, W and S have different marks. Only one person has scored between A and R. Only one person has scored between R and W. S has scored more than R and W. How many people have scored less than D?

The correct option is One.

Let us analyze the marks of the five people: D, R, A, W, and S. Let us represent their relative scores in descending order (from highest score to lowest score).

1. We are given that only one person scored between A and R. This means there is exactly one position separating A and R in the ordering. This gives us two possible relative placements:
Case A: A > [one person] > R
Case B: R > [one person] > A

2. We are also given that only one person scored between R and W. This means there is exactly one position separating R and W. Let's combine this with the previous condition. Since R is in the middle of both pairs, R must be separated by exactly one person from both A and W. This leads to two main structural arrangements:
Arrangement 1: A and W are on opposite sides of R. That is, A > [one person] > R > [one person] > W, or vice versa (W > [one person] > R > [one person] > A). Let's write down this layout for five positions:
Position 1 (Highest) - Position 2 - Position 3 - Position 4 - Position 5 (Lowest)
If we place R in the middle (Position 3), then A and W must occupy Position 1 and Position 5. This fits perfectly since there is exactly one person (at Position 2) between Position 1 and Position 3, and exactly one person (at Position 4) between Position 3 and Position 5.
So, the order is either A > _ > R > _ > W or W > _ > R > _ > A.

3. We are told that "S has scored more than R and W".
If the order is A > _ > R > _ > W:
S must be higher than both R (Position 3) and W (Position 5). The empty spots are Position 2 and Position 4. S cannot be at Position 4 because then S would be lower than R. Therefore, S must occupy Position 2. This leaves Position 4 for the remaining person, D.
Let us write down this complete order:
Position 1: A
Position 2: S
Position 3: R
Position 4: D
Position 5: W
Let us check all the conditions for this arrangement:
- A, S, R, D, W all have different marks: Yes.
- Only one person scored between A and R: Yes, S is between them.
- Only one person scored between R and W: Yes, D is between them.
- S scored more than R and W: Yes, S is at Position 2, while R is at Position 3 and W is at Position 5.
All conditions are fully satisfied.

4. In this arrangement (A > S > R > D > W), the people who scored less than D are those positioned below Position 4. The only person in this position is W (Position 5).
Therefore, exactly 1 person (W) has scored less than D.